Addressing Smoke Issues and Low Compression

Motorcycle engines, including those of pit bikes, may occasionally emit a small amount of smoke. However, when a persistent and substantial volume of smoke is observed, it is imperative to investigate and resolve the underlying problem.

Guidelines for Engine Maintenance

1. Breaking in New Engines
   It is essential to break in new pit bikes and engines using petroleum-based oil (non-synthetic).

2. Common Causes of Smoke in Used or Worn Engines
   Engines that exhibit smoke may be experiencing the following issues:

   • Worn or Damaged Piston Rings
     The piston rings may be worn out or broken, leading to smoke emission.
   • Degraded Piston
     The piston, a component subject to wear, should be replaced with every alternate ring change.
   • Deteriorated Valve Seals
     Worn valve seals can contribute to smoke production.

3. Valve Sealing Surface Concerns

   • Carbon Build-Up on Valves
     Excessive carbon accumulation on the valves may result in leakage.

4. Torque Specifications for CRF50 Type Engines
   Ensure that the top head nuts are torqued to a minimum of 110 in-lbs on CRF50 type engines.